First Time Past 400: 24-Shot Group Evaluation at 420 Yards (Seated Tripod / Arca / 17.5° Uphill)

[DRT-Hauler]

Hey guys,

Just joined the forum. Been lurking for a few years now.

Looking for some objective feedback on a recent training session. This was my first time ever stretching a rifle out past 400 yards. It is difficult to find any areas that allow for longer shots due to the topography of the land where I live. This isn't typically long range to most guys, but I have to start somewhere!

I am a newer shooter (3 years now) but I have very good mountain hunting available to me. This year I have been rucking since February in order to get in shape for the coming season (47, 5'6", 186lbs down to 162lbs). I wanted to test my real-world field capability from positions I might actually encounter on a mountain, so I set up on a gravel forest service road (FSR) with an approximately 10% road grade, shooting steep uphill at a target positioned with a 17.5° look angle.


My Setup:

• Rifle: SIG Cross in 6.5 Creedmoor +Heller Arms 3PRT Brake (Total weight with optics: 9lbs8oz).
• Optic: Burris Veracity PH 4-20x50.
• Mount: Sirui AM324 with spikes, Leophoto EB35 ballhead. Small 2.5" Arca rail directly locked into a tripod ball head. DIY sling tensioner. (The ball head was locked but able to move with moderate pressure).
• Ammo: Barnes VOR-TX Factory 127gr LRX.
• Chrono Data: 2,774 FPS average muzzle velocity (elevation when tested was 640ft ASL)

The Scenario:

• Time/ Weather: 0900 Pacific, 18C/ 65F, Overcast
• Distance: 420 yards on the HUD.
• Angle: 17.5° uphill incline (378 ft elevation gain).
• Position: Seated directly on the gravel FSR (no bum pad), rifle balanced on the ball head (no dedicated mechanical rear support).
• Tension System: I built myself a tension strap that I hook into the rifle swivel mount in front of the ball head, then carabiner it to my belt loop. This was made from an elastic-style single-point sling. Got the idea from a commercially available item.
• Course of Fire: 24 consecutive shots.

The Execution:

To establish a baseline for my raw mechanics, I chose not to call the wind or hold for it, simply because I have no experience with wind-calling at this time. I dialed my elevation into the Burris HUD to get my vertical solution and focused entirely on breaking clean shots.
The Results (See Attached Images):
I measured every single bullet hole's radial distance from the exact center of the bullseye (in millimeters). Here is the raw breakdown:

• Total String: 1.693 1.772 2.205 2.520 2.874 3.071 3.189 3.346 3.386 3.622 3.661 3.701 3.740 3.937 4.331 4.449 4.449 5.079 5.197 6.417 7.165 9.488 9.843 9.961
• Closest shot: 1.693 (0.38 MOA from center).
• Average deviation (Mean Radius): 4.543 (1.03 MOA from center).
• Furthest flyers: 9.488 9.843 9.961
• (~2.26 MOA from center).
• Overall group shape: The core 19 shots are tight, but the overall group shows a distinct push up and to the right..

Because I didn't hold for wind, the horizontal drift makes sense for a shifting breeze. However, I’m seeing about 12 inches of total vertical dispersion from the very lowest shot to those top three flyers.


My Questions for the Forum:

1. Given this is my first time out past 400 yards (or even close to that), the position (seated/Arca ball head/17.5° incline), and a 24-shot sample size, how can I improve on this?
2. What is the best way to start figuring out wind?
3. What is the best way to eliminate that vertical stringing?
4. What field-practical modifications can I make to my position to stabilize the rear when craning upward at a steep angle? I felt like the buttstock wasn't always placed in the optimum shoulder position.

This is all new to me and my goal is to be breaking clean shots consistently. I am open to suggestions on changing projectiles etc. I do not reload and will not be looking at that avenue for some time. I like the rifle and I find I am shooting it better than my 7RM. I believe that is down to the lesser felt recoil.

Appreciate the blunt feedback. Tear it apart.

 

[MallardSX2]

Stop reporting in MM's. This is an American site.

Your furthest miss was 10".

 

[Castle Rock]

Looks like inches to me
I would concentrate on being square to the rifle and constant cheek pressure, as well as the same height of butt placement.
It may also be that your rifle isn’t precisely zeroed.

 

[RWT]

Curious what your 10-20 shot 100 yard group under same conditions/positioning looks like?

 

[J.B.]

Far from an expert, but I would get comfortable shooting at distance from prone, and then start positional shooting.

 

[MallardSX2]

AI post at its finest right here.

Strange $hit on the internet these days.

 

[DRT-Hauler]

Looks like inches to me
I would concentrate on being square to the rifle and constant cheek pressure, as well as the same height of butt placement.
It may also be that your rifle isn’t precisely zeroed.

Right on. Thank you for the reply.

Yah I chaged that up after buddy there dropped his soother or his butt plug, not sure which it was.

It definitely feels different in the shoulder sitting down pointing up, compared to level off the table/bipod. Rifle is good at 100 yards and does cloverleaf occasionally. I'm currently shooting 1.2 MOA average for 5 shot groups at 100 yards. I'm not an expert by any means and joined this community to help improve my shooting capabilities.

 

[DRT-Hauler]

Curious what your 10-20 shot 100 yard group under same conditions/positioning looks like?

Only shot 5 shot groups at 100 yards , never 10 or 20 shot groups unless it's the 22lr. They are ammincable. Rifle shoots far better than I can and probably than I ever will. Larger shot groups are new to me and so is the longer range.

 

[Blake C]

What size group did the first 3 make?

 

[DRT-Hauler]

What size group did the first 3 make?

Blake I couldn't tell you but I'll check this on the next trip. I just took position and shot . Now that I think about it I could have let the barrell cool much longer between strings.

It's a decent drive back up the switchbacks to the target, so I was just hoping that I was on paper to be honest.

I'll be going out again next week, once work duty permits. I will take into consideration the points here given, starting with confirming my 100 yard zero and progressing from there.

Really appreciate those that took the time out of their day to post positive comments.

Thank you

 

[Blake C]

Blake I couldn't tell you but I'll check this on the next trip. I just took position and shot . Now that I think about it I could have let the barrell cool much longer between strings.

It's a decent drive back up the switchbacks to the target, so I was just hoping that I was on paper to be honest.

I'll be going out again next week, once work duty permits. I will take into consideration the points here given, starting with confirming my 100 yard zero and progressing from there.

Really appreciate those that took the time out of their day to post positive comments.

Thank you

Could be a combo of barrel heating and fatigue on your body. Prone is a good baseline. Then go for alternative positions..

 

[Truck24hr]

Do you have anything to verify you're not canting the rifle, and yes, if cheek pressure isn't there, roll up a towell around the stock as a temporary check to see if a more positive cheek weld.

 

[J.B.]

Blake I couldn't tell you but I'll check this on the next trip. I just took position and shot . Now that I think about it I could have let the barrell cool much longer between strings.

It's a decent drive back up the switchbacks to the target, so I was just hoping that I was on paper to be honest.

I'll be going out again next week, once work duty permits. I will take into consideration the points here given, starting with confirming my 100 yard zero and progressing from there.

Really appreciate those that took the time out of their day to post positive comments.

Thank you

If possible, get a target that will give you instant feedback. Ar500 is nice, but not necessary. I have a couple of mild steel targets that have held up for years, albeit they are very scarred lol. Something in the 10” range is a good starting point. Check with a local metal recycler, and look for something at least 3/4” thick. 1” is better.
If they have Ar500, 1/2” is plenty.

 

[Chris in TN]

Get a scope level. $20 and it'll help you eliminate questions, if nothing else.

I wouldn't worry about barrel heat with modern barrels. Especially if you're breaking and rebuilding position every 2-3-4 shots, which you should be doing, as you need training on building the positions as much or more than you need practice shooting from them.

Get a big steel target. There's no way I'd pay a single dollar for a target made of less than AR500 steel, for centerfire rifle use. I have a big disc blade I shoot at with .22lr, and only .22lr, but for everything else, just get a big AR500 gong. Buy once, cry once, and never worry about reverse ricochets. I adopted this stance about three seconds after a .45ACP round hit the ceiling of the porch I was shooting from one day ~20 years ago.

(3/8" AR500 is plenty for impacts under 2800'ish)

Eliminate the worst 20% or less of your shots and the rest are absolutely not bad at all, and for a first-timer, you did well. Don't lose sight of that. Remember that this is supposed to be fun.


ETA: Also, find some cheaper ammo.